Five arrested after 'homemade bomb' found in Paris

The Paris prosecutor has opened an anti-terror investigation after the discovery at the weekend of a homemade bomb at a building in Paris and five people have been arrested, sources close to the case said Monday.

Police discovered two cylinders of gas in the hall of a building in the city's 16th arrondissement and two others on the sidewalk. They also found a mobile phone linked to the cylinders, which appeared to be "a device to ignite" the explosive, the sources said.

A local resident alerted police after finding two of the gas cylinders around 4:30 am (0230 GMT) on Saturday, a source close to the probe said.

According to another source, four of the suspects were being held in custody Monday night.

The terrorist threat remains high in France which has been hit with a series of jihadist attacks since January 2015.